Reversible eccentric.



UNITED STATES PATENT orrron.

REVERSIBLE ECCENTRIC.

Specification of Letters Patent;

Patented Aug, 28, ,1906.

Application filed October 2,1905. Serial No. 281.024.

Ton/U whom it may concern:

Be it known that I, CLARENCE E. RISHEL, a citizen of the United States, residing at Ohama, in the county of Rio Arriba and Ter- .ritory of New Mexico, have invented certain new and useful Improvements in Reversible Eccentrics, of which the following is a speci fication.

This invention relates to certain improvements in that type of valve-reversingmechani'sm for engines wherein the 'reversal'of the direction ofmotion is effected by the shifting of an eccentric connected with the valve; andit consists in, certainpeculiarities in the con struction and. arrangement of parts and in certain.novelicombinations of elements substantially as hereinafter described, and particularly pointed out in the subjoined claims.

The main or ultimate object of the invention. is to provide a reversing mechanism of the type stated which will be of the highest efiiciency.

Among the subsidiary objects of the invention the following may be mentioned: First, to provide a reversing-valve gear comprising a shifting eccentric adapted to be moved across the shaft, which eccentric in its move ment from either side of said shaft to the other side thereof will preserve its lead of the valve; second, to provide means between the shaft and the eccentric and between said shaft and the eccentric-adjusting wedges for properly guiding said eccentric and wedges in the predetermined. movements, thereby adding to the efficiency anddurability of the gear; third, to provide a reversing-valvegear mechanism adapted to be used on 1000- motive-axles and which will be unafiected by movement laterally of said axle in so far as transmitting any movement therefrom to the valve-rod is concerned. These objects are welll accomplished by the construction illustrated in the accompanying drawings, which construction has been selected to exemplify what is at present regarded as the best em bodiment of the invention.

In said drawings, Figure 1 is a plan view showing the invention applied to a locomotive. Figs. 2 and 3 are detail views of an axle or shaft with the shifting eccentric and its operating means therein, respectively, showing the same at the extremes of their positions, said means being viewed from the side opposite that upon which is located the means for. sliding the wedges. Fig. 4 is a said collar.

horizontal section through theeccentric and its operating mechanism.

The same reference characters designate" the same parts in the several views.

A designates the driving-shaft of the en gine, which is journaled in bearings secured to a part of the engine-frame B. Mounted upon said shaft A is the eccentric 0, provided with an eccentric-strap D, the rod 01 of which V is connected with the valve-rod (not shown) preferably by the means hereinafter specified. It will be understood that the eccentric is adjustable on the shaft and that its adjustment causes a corresponding movement ofthe valve, which efiects a reversal-of the engine. This adjustment of the eccentric is transversely ofthe shaft A and is effected'by means which include Wedges E E{ and devices for sliding said of the shaft, which devices may be desirab composed of a sliding collar F, havingb a groove f, and bent lever G, fulcrumed etween its ends (at g) on a fulcrum-barb and having at one end a yoke g and at its other end a reach-rod H, by which it is connected to the reversing-lever. (Not shown.)

It is apparent that the wedges Eland'E are suitably secured to opposite sides of the collar F, for example, by providing themwith arms a e, screwed to said; collar, as shown. It is further apparent that the yoke g partially embraces said collar'and en ages" the groovedportion f thereof. The inclined or wedge-shaped ed es of the wedges EEf extend reversely with each other, one, as E, having its end'of greatest diameter presented toward the collar F, while the other, as-E,

has its end of least diameter located toward Said inclined edges of the;

respective wedges bear upon opposite inner walls of the central aperture 0 of the eccentric C, the surface of each of which walls preferably extends in diverging planes outwardly from a place near the center; thereof, as shown at 1 and 2 in Fig. 4., inv order to assure proper operation ofthe parts. The edges of the wedges opposite their in+ clined ones are fiat and bear upon contigu- 'ous edges of a bearin block I, which is fixedly mounted on the s aft A and has grooves or passages i in its said edges, which grooves" orpassages receive the portions ofthe wedges which are contiguous to and on opposite sides of said shaft A and guide said wedges in their movements.

wedges longitudinally l The other edges or sides 2" of the bearingblock I bear upon the contiguous walls 3 and 4, respectively, of the aperture in the eccentric O. Attention is called to the fact that said walls 3 and 4 form segments of circles which are concentric with each other and eccentric to the axis of the shaft A, on opposite sides of which they are arranged, and the edges t of the bearing-block I are of shape corresponding to said walls 3 and 4, one of said edges i being convex and the other concave and the curvatures of both being alike, whereby they bear throughout their lengths upon the concave wall 3 and convex wall 4, respectively, of said aperture 0. The sides t of the bearing-block I are preferably prolonged above and below said convex and. concave edges,respectively, and engage the sides of the eccentric C, thus forming channels or grooves in opposite sides of said block, which receive portions of said eccentric contiguous to the aperture 0 therein, and of which channels or grooves the edges 3 and 4 form the beds or bases. It will now be seen that when it is desired to reverse the engine from or into the proper direction of movement of its arts the engineer shifts his reversingever in the proper direction, thus sliding the collar F toward or from the eccentric, as the case may be, and corres ondingly adjusting the wed es E and E, W 'ch move the eccentric bodi y across the shaft A and cause it to 0perate the valve in the well-known manner to effect the reversal desired. Attention is called to the fact that the bearing-block I causes the eccentric in passing from either of its positions-across the center to travel in a curvilinear direction, which causes it to turn slightly ahead, and thereby increases the lead of the valve and at the same time decreases the travel of the same. The eccentric crosses the shaft at right angles with the crankin. In other words, the eccentric trave s ninety degrees ahead of the crank-pin. As this would only overcome the lap of the valve and does not give any lead or opening and to turn the eccentric farther ahead on the shaft, as in the case-of a single eccentric, would throw the travel that much behind when reversed, I accomplish the required lead by making the hole in the bearing-block back of its center as it stands in starting position with crank-pin in center throwing the whole eccentric ahead, and as the same side is always the driving side of my eccentric the lead will be the same when reversed. If it were not for the curved motion and the eccentric moved straight across the shaft, it would hold its lead on the forward stroke and lose it on the backward stroke as it was drawn toward the center.

For purposes of exemplifying the invention it is illustrated as applied for use on a locomotive in which the axles shift endwise. In such instance the shaft A is the locomotive-axle and the fulcrum-bar b is separate from the engine-frame and is employed to overcome the tendency of continual shifting of the wedges and consequent shifting of the valves by the shifting of the axle. Said fulcrum-bar is mounted on the axle at b by suitable means, which cause it to partake of the lateral but not of the rotative movements of said axle, and its connection with the lever G is such that it communicates said lateral movement to the latter. Said bar may have bearings in a supporting-bracket fixed either to the frame or to the boiler, and in which bearings it is adapted to slide.

A suitable means for connecting the eccentric-rod (Z with the valve comprises a rock-shaft J, to which is fixed a rocker-arm K, which is connected with said eccentricrod, as shown at 76, and in practice is also suitably connected with therod of the valve. (Not shown.)

Having thus described the invention, What I believe to be new and desire to secure by Letters Patent, and what I therefore claim, 1s

1. A reversing-valve gear for engines, comprising a shifting eccentric having an aperture opposite sides of which are formed with curvilinear walls, a shaft extending through said aperture, a bearing-block mounted on said shaft and having opposite edges curved to correspond with said curvilinear walls and engaging the same, sliding wedges arranged on opposite sides of the shaft and having their inclined edges engaged with the other walls of said. eccentric and their other edges engaged with said block, and means for sliding said wedges.

2. A reversing-valve gear for engines, comprising a shifting eccentric having an aperture two opposite sides of which are formed with curvilinear walls, a shaft extending through said aperture, sliding wedges arranged on opposite sides of said shaft and having their mclined edges engaged with the other walls of said aperture, means for sliding said wedges, and a bearing-block mounted on said shaft within said aperture and provided on all of its edges with grooves, two of which receive the contiguous portions of said wedges and the other two of which receive the portions of said eccentric contiguous to the curvilinear walls of said aperture and are curved to correspond with and engage the latter, and means for connecting said-eccentric with the rod of the valve to be shifted thereby.

3. The combination with a locomotiveaxle, of a reversing-valve-gear mechanism mounted thereon and partaking of the lateral movements thereof, means for im arting movement to said valve-gear mechanism with relation to said axle for the purpose IIO specified, said means also partaking of the trio bodily upon said shaft during such shift- I0 lateral movement of said axle. ing motion.

4. In a device of the character described, In testimony whereof I affiX my signature the combination w1th an engine-shaft, of in presence of two witnesses.

wed es slidable lon itudinally with relation to said shaft, an ecc entric having an opening CLARENCE RISHEL' formed therethrough with which said Wedges Witnesses:

engage to shift said eccentric transversely of J AMES WALsH,

the shaft and means for turning said eccen- O. E. ROGERS. 

